1. Field of the Invention
The present invention is directed to a grease extractor, and more particularly to a grease extractor in which grease laden air is forced to flow through a membrane filter and is deflected on a trap member disposed downstream of the filter for removal of the grease by deposition on the trap member.
2. Description of the Prior Art
In a factory operating lathes and grinders, there has been a potential hazard of contaminating environment with grease employed in the operation of the lathes and grinder. To remove the grease from grease laden air, grease extractors have been widely utilized in the art. As disclosed in Japanese Utility Model Publication (KOKOKU) No. 58-11373, most of the prior grease extractors are designed to operate on a basic principle of forcibly flowing the grease laden air through one or more filters to seize the grease thereat. For increased grease trapping capacity, the filter is required to be of relatively thick. However, the use of such thick filter poses a problem that the filter when saturated with the grease will impede the forced air flow to reduce the volume of flow, remarkably lowering grease removal efficiency. Therefore, the filter has to be replaced frequently. Additionally, in the prior grease extractor it is a general practice to design blow capacity of a fan responsible for generating the forced air flow in accordance with an initial flow resistance of the filter. Consequently, as the grease accumulates in the filter, the volume of flow will reduce to lower the grease trapping efficiency within the life time of the filter, which makes it impossible to obtain a consistent grease trapping efficiency over the operational life of the grease extractor.